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Alternaria is a ubiquitous genus that may infect wheat in many countries, causing the disease black point. The present study aimed to assess contamination by fungi, of durum wheat kernels from Lebanon, and identify the main Alternaria species contaminants. Alternaria was detected in the majority (97%) of the inspected fields. Contamination by Alternaria differed among the samples according to their geographical origins. The greatest contamination was detected in the West Bekaa area (average 59%), followed by Akkar (55%), and lowest was observed in Baalbeck (2%). HPLCDAD analyses performed on grain samples showed that altenuene, alternariol, alternariol monomethyl ether, and tenuazonic acid were not detected in any sample. Phylogenetic analyses, based on DNA sequences of ß-tubulin, glyceraldehyde-3-phosphate dehydrogenase and calmodulin gene fragments, showed that Alternaria field strains belonged to two major sections: Alternaria (51%) and Infectoriae (40%). The remaining strains were in separate clades in sections Ulocladioides (3%), Chalastospora (3%) and Pseudoalternaria (3%). Although this study revealed no contamination of wheat kernels by Alternaria mycotoxins, the potential risk of mycotoxin accumulation remains high due to the widespread occurrence of toxigenic Alternaria species on kernels. [ABSTRACT FROM AUTHOR]

The tomato is one of the most consumed agri-food products in Lebanon. Several fungal pathogens, including Alternaria species, can infect tomato plants during the whole growing cycle. Alternaria infections cause severe production and economic losses in field and during storage. In addition, Alternaria species represent a serious toxicological risk since they are able to produce a wide range of mycotoxins, associated with different toxic activities on human and animal health. Several Alternaria species were detected on tomatoes, among which the most important are A. solani, A. alternata, and A. arborescens. A set of 49 Alternaria strains isolated from leaves and stems of diseased tomato plants were characterised by using a polyphasic approach. All strains were included in the recently defined phylogenetic Alternaria section and grouped in three well-separated sub-clades, namely A. alternata (24 out of 49), A. arborescens (12 out of 49), and A. mali morpho-species (12 out of 49). One strain showed high genetic similarity with an A.limoniasperae reference strain. Chemical analyses showed that most of the Alternaria strains, cultured on rice, were able to produce alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT) and tenuazonic acid (TA), with values up to 5634, 16,006, 5156, and 4507 mg kg−1, respectively. In addition, 66% of the strains were able to co-produce simultaneously the four mycotoxins investigated. The pathogenicity test carried out on 10 Alternaria strains, representative of phylogenetic sub-clades, revealed that they were all pathogenic on tomato fruits. No significant difference among strains was observed, although A. alternata and A. arborescens strains were slightly more aggressive than A. mali morpho-species strains. This paper reports new insights on mycotoxin profiles, genetic variability, and pathogenicity of Alternaria species on tomatoes. [ABSTRACT FROM AUTHOR]

The emerging Alternaria mycotoxins tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT) and tentoxin (TTX) are not yet regulated worldwide awaiting for more data on their toxicity and natural occurrence. A total of 131 samples of spices (94) and herbs (37) were collected in Beirut (Lebanon) markets and analysed for TeA, AOH, AME, ALT and TTX by using a UPLC-MS/MS method based on 'extract, dilute and shoot' approach. High percentage (89%) of samples were contaminated by 1–5 mycotoxins whereas 14% of samples were contaminated with a mixture of TeA, AOH, AME and TTX. TeA was the predominant mycotoxin with the highest percentages of positive samples (76%), followed by AME (46%), TTX (37%), AOH (34%) and ALT (5%) with overall mean/max levels of 2453.2/106792.8, 17.1/306, 14.8/179.4, 35.0/636.4 and 2.8/22.1 μg/kg, respectively (middle bound approach). Higher percentage of positive samples and mean mycotoxin levels were observed in spices as compared to herbs. The spices with higher levels of mycotoxin contamination were, in descending order, red chili, paprika, caraway, coriander seeds, onion powder, white pepper and garlic powder whereas within the herbs they were corn silk, violets and marjoram. Based on the mean levels of TeA measured in different spices and herbs, the daily consumption of >3.3 g red chili, >3.7 g paprika, >16.7 g caraway or >36 g of corn silk will exceed the threshold of toxicological concern (TTC) of TeA (1,500 ng/kg bw per day). For AOH or AME the TTC (2.5 ng/kg bw/day) will be exceeded by a daily consumption >0.5 g of white pepper, >0.9 g of onion powder, > 1.4 g of garlic powder, >1.7 g of black pepper, >1.9 g of sage, >3.3 g of violets or > 4.4 g of thyme leaves. This study provide large information on the natural occurrence of Alternaria mycotoxins in spices and herbs useful for the human exposure assessment and future regulation. • 131 spices/herbs marketed in Lebanon were analysed for Alternaria mycotoxins. • 89% of samples were contaminated by 1–5 mycotoxins. • Spices resulted more susceptible than herbs to mycotoxins contamination. • The spice/herbs more susceptible to toxins contamination were identified. • Occurrence data of mycotoxins in spices/herbs useful for human exposure assessment. [ABSTRACT FROM AUTHOR]